Add Document::print_node and C FFI for it

Author: shadowfacts

crates/core/c_src/include/LiveViewNativeCore.h

@@ -42,6 +42,8 @@ typedef struct __Node {
 
 extern _RustString __liveview_native_core$Document$to_string(__Document doc);
 
+extern _RustString __liveview_native_core$Document$node_to_string(__Document doc, NodeRef node);
+
 extern __Document __liveview_native_core$Document$empty();
 
 extern void __liveview_native_core$Document$drop(__Document doc);

crates/core/src/dom/mod.rs

@@ -557,7 +557,17 @@ impl Document {
 
     /// Prints this document using the given writer and options
     pub fn print(&self, writer: &mut dyn fmt::Write, options: PrintOptions) -> fmt::Result {
-        let printer = Printer::new(self, self.root, options);
+        self.print_node(self.root, writer, options)
+    }
+
+    /// Prints a node in this document using the given writer and options
+    pub fn print_node(
+        &self,
+        node: NodeRef,
+        writer: &mut dyn fmt::Write,
+        options: PrintOptions,
+    ) -> fmt::Result {
+        let printer = Printer::new(self, node, options);
         printer.print(writer)
     }
 }

crates/core/src/ffi/mod.rs

@@ -130,6 +130,15 @@ pub extern "C" fn document_to_string(doc: *mut dom::Document) -> RustString {
     RustString::from_string(doc.to_string())
 }
 
+#[export_name = "__liveview_native_core$Document$node_to_string"]
+pub extern "C" fn document_node_to_string(doc: *mut dom::Document, node: NodeRef) -> RustString {
+    let doc = unsafe { &*doc };
+    let mut buf = String::new();
+    doc.print_node(node, &mut buf, dom::PrintOptions::Pretty)
+        .expect("error printing node");
+    RustString::from_string(buf)
+}
+
 #[export_name = "__liveview_native_core$Document$merge"]
 pub extern "C" fn document_merge(doc: *mut dom::Document, other: *const dom::Document) -> bool {
     let doc = unsafe { &mut *doc };